Endocrinology
Abstract
As a highly regenerative organ, the intestine is a promising source for cellular reprogramming to replace lost pancreatic β-cells in diabetes. Gut enterochromaffin cells can be converted to insulin-producing cells by FoxO1 ablation, but their numbers are limited. In this study we report that insulin-immunoreactive cells with Paneth/goblet cell features are present in human fetal intestine. Accordingly, lineage tracing experiments show that upon genetic or pharmacologic FoxO1 ablation the Paneth/goblet lineage can also undergo conversion to the insulin lineage. We designed a screening platform in gut organoids to accurately quantitate β-like cell reprogramming and fine-tune a combination treatment to increase the efficiency of the conversion process in mice and human adult intestinal organoids. We identified a triple blockade of FOXO1, Notch, and TGFβ that, when tested in insulin-deficient STZ or NOD diabetic animals resulted in near-normalization of glucose levels, associated with the generation of intestinal insulin-producing cells. The findings illustrate a therapeutic approach to replace insulin treatment in diabetes.
Authors
Wen Du, Junqiang Wang, Taiyi Kuo, Liheng Wang, Wendy M. McKimpson, Jinsook Son, Hitoshi Watanabe, Takumi Kitamoto, Yun-Kyoung Lee, Remi J. Creusot, Lloyd E. Ratner, Kasi McCune, Ya-Wen Chen, Brendan H. Grubbs, Matthew E. Thornton, Jason Fan, Nishat Sultana, Bryan S. Diaz, Iyshwarya Balasubramanian, Nan Gao, Sandro Belvedere, Domenico Accili
Abstract
BACKGROUND Hypoactive sexual desire disorder (HSDD) is characterized by a persistent deficiency of sexual fantasies and desire for sexual activity, causing marked distress and interpersonal difficulty. It is the most prevalent female sexual health problem globally, affecting approximately 10% of women, but has limited treatment options. Melanocortin 4 receptor (MC4R) agonists have emerged as a promising therapy for women with HSDD, through unknown mechanisms. Studying the pathways involved is crucial for our understanding of normal and abnormal sexual behavior.METHODS Using psychometric, functional neuroimaging, and hormonal analyses, we conducted a randomized, double-blinded, placebo-controlled, crossover clinical study to assess the effects of MC4R agonism compared with placebo on sexual brain processing in 31 premenopausal heterosexual women with HSDD.RESULTS MC4R agonism significantly increased sexual desire for up to 24 hours after administration compared with placebo. During functional neuroimaging, MC4R agonism enhanced cerebellar and supplementary motor area activity and deactivated the secondary somatosensory cortex, specifically in response to visual erotic stimuli, compared with placebo. In addition, MC4R agonism enhanced functional connectivity between the amygdala and the insula during visual erotic stimuli compared with placebo.CONCLUSION These data suggest that MC4R agonism enhanced sexual brain processing by reducing self-consciousness, increasing sexual imagery, and sensitizing women with HSDD to erotic stimuli. These findings provide mechanistic insight into the action of MC4R agonism in sexual behavior and are relevant to the ongoing development of HSDD therapies and MC4R agonist development more widely.TRIAL REGISTRATION ClinicalTrials.gov NCT04179734.FUNDING This is an investigator-sponsored study funded by AMAG Pharmaceuticals Inc., the Medical Research Council (MRC) (MR/T006242/1), and the National Institute for Health Research (NIHR) (CS-2018-18-ST2-002 and RP-2014-05-001).
Authors
Layla Thurston, Tia Hunjan, Edouard G. Mills, Matthew B. Wall, Natalie Ertl, Maria Phylactou, Beatrice Muzi, Bijal Patel, Emma C. Alexander, Sofiya Suladze, Manish Modi, Pei C. Eng, Paul A. Bassett, Ali Abbara, David Goldmeier, Alexander N. Comninos, Waljit S. Dhillo
Abstract
BACKGROUND. Cytochrome P450 Family 8 Subfamily B Member 1 (CYP8B1) generates 12α-hydroxylated bile acids (BAs) which were associated with insulin resistance in humans. METHODS. To determine if reduced CYP8B1 activity improves insulin sensitivity, we sequenced CYP8B1 in individuals without diabetes and identified carriers of complete loss-of-function (CLOF) mutations utilizing functional assays. RESULTS. Mutation carriers had lower plasma 12α-hydroxylated:non-12α-hydroxylated BA and cholic acid (CA):chenodeoxycholic acid (CDCA) ratios compared to age-, gender- and BMI-matched controls. During insulin clamps, hepatic glucose production was suppressed to a similar magnitude by insulin, but glucose infusion rates to maintain euglycemia were higher in mutation carriers, indicating increased peripheral insulin sensitivity. Consistently, a polymorphic CLOF CYP8B1 mutation associated with lower fasting insulin in the AMP-T2D-GENES study. Exposure of primary human muscle cells to carrier CA:CDCA ratios demonstrated increased FOXO1 activity, and upregulation of both insulin signaling and glucose uptake, which were mediated by increased CDCA. Inhibition of FOXO1 attenuated the CDCA-mediated increase in muscle insulin signaling and glucose uptake. We find that reduced CYP8B1 activity associates with increased insulin sensitivity in humans. CONCLUSION. Our findings suggest that increased circulatory CDCA due to reduced CYP8B1 activity increases skeletal muscle insulin sensitivity, contributing to increased whole-body insulin sensitization. FUNDING. This study was funded by BMRC/NMRC Bench and Bedside grant (BnB13Dec011) to HCT and RRS.
Authors
Shiqi Zhong, Raphael Chevre, David Castaño Mayan, Maria Corlianò, Blake J. Cochran, Kai Ping Sem, Theo H. van Dijk, Jianhe Peng, Liang Juin Tan, Siddesh V. Hartimath, Boominathan Ramasamy, Peter Cheng, Albert K. Groen, Folkert Kuipers, Julian L. Goggi, Chester Drum, Rob M. van Dam, Ru-San Tan, Kerry-Anne Rye, Michael R. Hayden, Ching-Yu Cheng, Shaji Chacko, Jason Flannick, Xueling Sim, Hong Chang Tan, Roshni R. Singaraja
Abstract
BACKGROUND. Studies in cell cultures and rodents suggest that toll-like receptor (TLR)4 is involved in the pathogenesis of insulin resistance, but direct data in humans are limited. We tested the hypothesis that pharmacologic blockade of TLR4 with the competitive inhibitor eritoran would improve insulin resistance in humans. METHODS. In Protocol I, 10 lean, healthy subjects received the following 72-h intravenous (I.V.) infusions in a randomized crossover design: saline (30 ml/h)+vehicle; Intralipid® (30 ml/h)+vehicle; or Intralipid® (30 ml/h)+eritoran (12 mg I.V. every 12 h). In Protocol II, 9 obese, non-diabetic subjects received eritoran (12 mg I.V. every 12 h) or vehicle for 72 h, also in a randomized crossover design. The effects of eritoran were assessed with a euglycemic, hyperinsulinemic clamp. RESULTS. In Protocol I, lipid infusion significantly decreased peripheral insulin sensitivity (M value) by 14% and increased fasting plasma glucose (FPG), fasting plasma insulin (FPI) and HOMA insulin resistance index (HOMA-IR) by 7%, 22%, and 26%, respectively. Eritoran did not prevent lipid-induced alterations in these metabolic parameters. Eritoran also failed to improve any baseline metabolic parameters (M, FPG, FPI, HOMA-IR) in obese, insulin-resistant subjects (Protocol II). CONCLUSIONS. Acute TLR4 inhibition with eritoran did not protect against lipid-induced insulin resistance. Short-term eritoran administration also failed to improve obesity-associated insulin resistance. These data do not support a role for TLR4 in insulin resistance. Future studies with a different class of TLR4 inhibitors, longer drug exposure, and/or lipid-enhancing interventions richer in saturated fats may be needed to further clarify the role of TLR4 on metabolic dysfunction in humans. TRIAL REGISTRATIONS. ClinicalTrials.gov NCT02321111, NCT02267317 FUNDING. NIH grants R01DK080157, P30AG044271, P30AG013319 and UL1TR002645.
Authors
Hanyu Liang, Nattapol Sathavarodom, Claudia Colmenares, Jonathan Gelfond, Sara E. Espinoza, Vinutha Ganapathy, Nicolas Musi
Abstract
Insulin resistance is a fundamental pathogenic factor that characterizes various metabolic disorders, including obesity and type 2 diabetes. Adipose tissue contributes to the development of obesity-related insulin resistance through increased release of fatty acids, altered adipokine secretion, and/or macrophage infiltration and cytokine release. Here, we aimed to analyze the participation of the cyclin-dependent kinase 4 (CDK4) in adipose tissue biology. We determined that white adipose tissue (WAT) from CDK4-deficient mice exhibits impaired lipogenesis and increased lipolysis. Conversely, lipolysis was decreased and lipogenesis was increased in mice expressing a mutant hyperactive form of CDK4 (CDK4R24C). We performed a global kinome analysis and found that mice lacking Cdk4 had impaired insulin signaling in the adipose tissue. Interestingly, our results demonstrated that insulin activates the cyclin D3-CDK4 complex, which, in turn, phosphorylates the insulin receptor substrate 2 (IRS2) at the Ser 388, likely creating a positive feedback loop to maintain adipocyte insulin signaling. Furthermore, we found that CCND3 expression and IRS2 serine 388 phosphorylation are increased in human obese subjects. Together, our results demonstrate that CDK4 is a major regulator of insulin signaling in WAT.
Authors
Sylviane Lagarrigue, Isabel C. Lopez-Mejia, Pierre-Damien Denechaud, Xavier Escoté, Judit Castillo-Armengol, Veronica Jimenez, Carine Chavey, Albert Giralt, Qiuwen Lai, Lianjun Zhang, Laia Martinez-Carreres, Brigitte Delacuisine, Jean-Sébastien Annicotte, Emilie Blanchet, Sébastien Huré, Anna Abella, Francisco J. Tinahones, Joan Vendrell, Pierre Dubus, Fatima Bosch, C. Ronald Kahn, Lluis Fajas
Abstract
Resistance to regeneration of insulin-producing pancreatic beta cells is a fundamental challenge for Type 1 and Type 2 diabetes. Recently, small molecule inhibitors of the kinase DYRK1A have proven effective in inducing adult human beta cells to proliferate, but their detailed mechanism of action is incompletely understood. We interrogated our human insulinoma and beta cell transcriptomic databases seeking to understand why beta cells in insulinomas proliferate, while normal beta cells do not. This search suggested the DREAM complex as a central regulator of quiescence in human beta cells. DREAM complex consists of a module of transcriptionally repressive proteins that assemble in response to DYRK1A kinase activity, thereby inducing and maintaining cellular quiescence. In the absence of DYRK1A, DREAM subunits reassemble into the pro-proliferative MMB complex. Here we demonstrate that small molecule DYRK1A inhibitors induce human beta cells to replicate by converting the repressive DREAM complex to its pro-proliferative MMB conformation.
Authors
Peng Wang, Esra Karakose, Carmen Argmann, Huan Wang, Metodi Balev, Rachel I. Brody, Hembly G. Rivas, Xinyue Liu, Olivia Wood, Hongtao Liu, Lauryn Choleva, Dan Hasson, Emily Bernstein, Joao A. Paulo, Donald K. Scott, Luca Lambertini, James A. DeCaprio, Andrew F. Stewart.
Abstract
Hepatic inflammation is culpable for the evolution of asymptomatic steatosis to nonalcoholic steatohepatitis (NASH). Hepatic inflammation results from abnormal macrophage activation. We found that FoxO1 links overnutrition to hepatic inflammation by regulating macrophage polarization and activation. FoxO1 was upregulated in hepatic macrophages, correlating with hepatic inflammation, steatosis and fibrosis in mice and patients with NASH. Myeloid cell-conditional FoxO1 knockout skewed macrophage polarization from pro-inflammatory M1 to anti-inflammatory M2 phenotypes, accompanied by the reduction of macrophage infiltration in liver. These effects mitigated overnutrition-induced hepatic inflammation and insulin resistance, contributing to improved hepatic metabolism and increased energy expenditure in myeloid cell FoxO1 knockout mice on HFD. When fed a NASH-inducing diet, myeloid cell FoxO1 knockout mice were protected from developing NASH, culminating in the reduction of hepatic inflammation, steatosis and fibrosis. Mechanistically, FoxO1 counteracts Stat6 to skew macrophage polarization from M2 toward M1 signatures to perpetuate hepatic inflammation in NASH. FoxO1 appears as a pivotal mediator of macrophage activation in response to overnutrition and a therapeutic target for ameliorating hepatic inflammation to stem the disease progression from benign steatosis to NASH.
Authors
Sojin Lee, Taofeek O. Usman, Jun Yamauchi, Goma Chhetri, Xingchun Wang, Gina M. Coudriet, Cuiling Zhu, Jingyang Gao, Riley McConnell, Kyler Krantz, Dhivyaa Rajasundaram, Sucha Singh, Jon Piganelli, Alina Ostrowska, Alejandro Soto-Gutierrez, Satdarshan P. Monga, Aatur D. Singhi, Radhika H. Muzumdar, Allan Tsung, H. Henry Dong
Abstract
BACKGROUND Multiple islet autoantibodies (AAbs) predict the development of type 1 diabetes (T1D) and hyperglycemia within 10 years. By contrast, T1D develops in only approximately 15% of individuals who are positive for single AAbs (generally against glutamic acid decarboxylase [GADA]); hence, the single GADA+ state may represent an early stage of T1D.METHODS Here, we functionally, histologically, and molecularly phenotyped human islets from nondiabetic GADA+ and T1D donors.RESULTS Similar to the few remaining β cells in the T1D islets, GADA+ donor islets demonstrated a preserved insulin secretory response. By contrast, α cell glucagon secretion was dysregulated in both GADA+ and T1D islets, with impaired glucose suppression of glucagon secretion. Single-cell RNA-Seq of GADA+ α cells revealed distinct abnormalities in glycolysis and oxidative phosphorylation pathways and a marked downregulation of cAMP-dependent protein kinase inhibitor β (PKIB), providing a molecular basis for the loss of glucose suppression and the increased effect of 3-isobutyl-1-methylxanthine (IBMX) observed in GADA+ donor islets.CONCLUSION We found that α cell dysfunction was present during the early stages of islet autoimmunity at a time when β cell mass was still normal, raising important questions about the role of early α cell dysfunction in the progression of T1D.FUNDING This work was supported by grants from the NIH (3UC4DK112217-01S1, U01DK123594-02, UC4DK112217, UC4DK112232, U01DK123716, and P30 DK019525) and the Vanderbilt Diabetes Research and Training Center (DK20593).
Authors
Nicolai M. Doliba, Andrea V. Rozo, Jeffrey Roman, Wei Qin, Daniel Traum, Long Gao, Jinping Liu, Elisabetta Manduchi, Chengyang Liu, Maria L. Golson, Golnaz Vahedi, Ali Naji, Franz M. Matschinsky, Mark A. Atkinson, Alvin C. Powers, Marcela Brissova, Klaus H. Kaestner, Doris A. Stoffers, for the HPAP Consortium
Abstract
Glucocorticoid steroids are commonly prescribed for many inflammatory conditions, but chronic daily use produces adverse effects including muscle wasting and weakness. In contrast, shorter glucocorticoid pulses may improve athletic performance, although the mechanisms remain unclear. Muscle is sexually dimorphic and comparatively little is known about how male and female muscles respond to glucocorticoid steroids. We investigated the impact of once-weekly glucocorticoid exposure on skeletal muscle performance comparing male and female mice. One month of once-weekly glucocorticoid dosing improved muscle specific force in both males and females. Transcriptomic profiling of isolated myofibers identified a striking sexually dimorphic response to weekly glucocorticoids. Male myofibers had increased expression of genes in the IGF1/PI3K pathway and calcium handling, while female myofibers had profound upregulation of lipid metabolism genes. Muscles from weekly prednisone-treated males had improved calcium handling, while comparably treated female muscles had reduced intramuscular triglycerides. Consistent with altered lipid metabolism, weekly prednisone-treated female mice had greater endurance relative to controls. Using chromatin immunoprecipitation, we defined a sexually dimorphic chromatin landscape after weekly prednisone. These results demonstrate that weekly glucocorticoid exposure elicits distinct pathways in males versus females resulting in enhanced performance.
Authors
Isabella M. Salamone, Mattia Quattrocelli, David Y. Barefield, Patrick G. Page, Ibrahim Tahtah, Michele Hadhazy, Garima Tomar, Elizabeth M. McNally
Abstract
Type 2 diabetes (T2D) is associated with defective insulin secretion and reduced β cell mass. Available treatments provide a temporary reprieve, but secondary failure rates are high, making insulin supplementation necessary. Reversibility of β cell failure is a key translational question. Here, we reverse engineered and interrogated pancreatic islet–specific regulatory networks to discover T2D-specific subpopulations characterized by metabolic inflexibility and endocrine progenitor/stem cell features. Single-cell gain- and loss-of-function and glucose-induced Ca2+ flux analyses of top candidate master regulatory (MR) proteins in islet cells validated transcription factor BACH2 and associated epigenetic effectors as key drivers of T2D cell states. BACH2 knockout in T2D islets reversed cellular features of the disease, restoring a nondiabetic phenotype. BACH2-immunoreactive islet cells increased approximately 4-fold in diabetic patients, confirming the algorithmic prediction of clinically relevant subpopulations. Treatment with a BACH inhibitor lowered glycemia and increased plasma insulin levels in diabetic mice, and restored insulin secretion in diabetic mice and human islets. The findings suggest that T2D-specific populations of failing β cells can be reversed and indicate pathways for pharmacological intervention, including via BACH2 inhibition.
Authors
Jinsook Son, Hongxu Ding, Thomas B. Farb, Alexander M. Efanov, Jiajun Sun, Julie L. Gore, Samreen K. Syed, Zhigang Lei, Qidi Wang, Domenico Accili, Andrea Califano
Copyright © 2025 American Society for Clinical Investigation
ISSN: 0021-9738 (print), 1558-8238 (online)